[svn:parrot] r40934 - in trunk/src: . gc ops

[chromatic at svn.parrot.org]

Author: chromatic
Date: Thu Sep  3 00:10:47 2009
New Revision: 40934
URL: https://trac.parrot.org/parrot/changeset/40934

Log:
[PMC] Ensure that all accesses to PMC_sync check the PMC shared flag first, to
avoid dereferencing an absent PMC_sync structure.

Modified:
   trunk/src/gc/api.c
   trunk/src/hll.c
   trunk/src/ops/set.ops

Modified: trunk/src/gc/api.c
==============================================================================
--- trunk/src/gc/api.c	Wed Sep  2 23:57:29 2009	(r40933)
+++ trunk/src/gc/api.c	Thu Sep  3 00:10:47 2009	(r40934)
@@ -406,10 +406,13 @@
 Parrot_gc_add_pmc_sync(PARROT_INTERP, ARGMOD(PMC *pmc))
 {
     ASSERT_ARGS(Parrot_gc_add_pmc_sync)
+
+    /* This mutex already exists, leave it alone. */
     if (PMC_sync(pmc))
-        /* This mutex already exists, leave it alone. */
         return;
+
     PMC_sync(pmc) = mem_allocate_typed(Sync);
+
     if (!PMC_sync(pmc))
         Parrot_ex_throw_from_c_args(interp, NULL, EXCEPTION_ALLOCATION_ERROR,
             "Parrot VM: PMC Sync allocation failed!\n");

Modified: trunk/src/hll.c
==============================================================================
--- trunk/src/hll.c	Wed Sep  2 23:57:29 2009	(r40933)
+++ trunk/src/hll.c	Thu Sep  3 00:10:47 2009	(r40934)
@@ -53,7 +53,7 @@
 #define END_READ_HLL_INFO(interp, hll_info)
 #define START_WRITE_HLL_INFO(interp, hll_info) \
     do { \
-        if (PMC_sync((interp)->HLL_info)) { \
+	if (PObj_is_PMC_shared_TEST(obj) && PMC_sync((interp)->HLL_info)) { \
             (hll_info) = (interp)->HLL_info = \
                 Parrot_clone((interp), (interp)->HLL_info); \
             if (PMC_sync((interp)->HLL_info)) \
@@ -362,8 +362,8 @@
             "no such HLL ID (%vd)", hll_id);
 
     /* the type might already be registered in a non-conflicting way, in which
-     * case we can avoid copying */
-    if (PMC_sync(hll_info)) {
+     * ca se we can avoid copying */
+    if (PObj_is_PMC_shared_TEST(obj) && PMC_sync(hll_info)) {
         if (hll_type == Parrot_get_HLL_type(interp, hll_id, core_type))
             return;
     }

Modified: trunk/src/ops/set.ops
==============================================================================
--- trunk/src/ops/set.ops	Wed Sep  2 23:57:29 2009	(r40933)
+++ trunk/src/ops/set.ops	Thu Sep  3 00:10:47 2009	(r40934)
@@ -508,10 +508,10 @@
 
         /* don't let the clone's destruction destroy the destination's data */
         PObj_active_destroy_CLEAR(clone);
-        PMC_data(clone) = NULL;
-        PMC_metadata(clone) = NULL;
+	PMC_data(clone)        = NULL;
+	PMC_sync(clone)        = NULL;
+	PMC_metadata(clone)    = NULL;
         PMC_next_for_GC(clone) = NULL;
-        PMC_sync(clone) = NULL;
 
         /* Restore metadata. */
         if (!PMC_IS_NULL(meta)) {